In the prior art, as shown in FIG. 1(a), a combustion chamber is defined by a cylinder head and a piston. The diameter of the combustion chamber of the prior art is comparatively large and a combustion pressure and a combustion temperature are applied to the large area of the combustion chamber and piston. Since cooling is essentially required, as the combustion chamber increases in diameter and surface area, a cooling loss increases. Moreover, when increasing the maximum combustion pressure, a reinforcement depending on the combustion pressure is required, whereby the weight per output is increased. Similarly, when increasing the maximum combustion pressure, since the friction losses of a piston ring or the like are increased, the friction loss per output is increased.
At the moment of combustion, usually, a combustion period extends between nearly 40 deg. to 60 deg. in crank angle after the dead centers. However, when the piston begins to retract from the top dead center, the combustion chamber communicates with the cylinder, whereby in response to the retraction of the piston, the volume of the combustion chamber is increased rapidly. As a result, an extreme non-constant volume combustion is caused, so that the maximum combustion pressure and the maximum combustion temperature are lowered rapidly, whereby the combustion conditions deteriorate.
Moreover, when regulating the combustion conditions to reduce the generated NOx gases, the uncombusted portion of the fuel is increased, and when regulating the combustion conditions to reduce the uncombusted portion of the fuel, the generated NOx gases increase.
With reference to a pressure diagram of a constant pressure cycle engine shown in FIG. 2, another description is given. In the conventional constant pressure cycle engine, the major portion of the thermal energy generated by combustion, including the thermal energy at the maximum combustion pressure, is released as shown in FIG. 2, until 30 deg. in crank angle after the top dead center. Since before and after the top dead center, the friction loss is maximized, the thermal energy released is dissipated by the friction force, whereby the amount of work (a stroke volume of the piston) becomes extremely slight. On the one hand, at the best opportunity of 90 deg. in crank angle after the top dead center at which the friction loss is minimized and is most adapted to release the thermal energy, the thermal energy to be released is reduced by nearly one fourteenth, whereby thermal energy of nearly 30 percent is lost.
In the constant volume cycle engine, since the curves of a pressure diagram shown in FIG. 2 further is shifted to the top dead center side, thermal energy of 30 percent or more is lost.
That is, it has been the largest disadvantage in the prior art that the thermal energy to be released is released almost at the time when the friction loss is at a maximum.
The pressure diagram of the constant volume cycle engine shown in FIG. 2 is described as compared with the case where we make a bicycle to advance efficiently by pushing down vertically. In the conventional constant pressure cycle engine and the constant volume cycle engine, the major portion of the thermal energy generated by combustion is released from the top dead center to 30 deg. in crank angle after the top dead center. On the other hand, we do not attempt to release the entire energy in the vertical direction at the time when the bicycle pedal is at the top dead center. Especially, at 90 deg. in crank angle after the top dead center where the efficiency of the case of converting an up-and-down motion to rotating power becomes the best timing, the force to be applied to the bicycle pedal is never reduced to nearly one fourteenth.
Since we know well the laws of nature from the experimental laws, at the time when the bicycle pedal is at the top dead center, the force to be applied to the bicycle pedal is reduced to the minimum required, and to the timing of 90 deg. in crank angle after the top dead center where the efficiency of converting the up-and-down motion to rotating power becomes its maximum, the force to be applied to the bicycle pedal is expanded increasingly.
That is, at the top dead center, the friction loss is maximized, so that the efficiency of converting the up-and-down motion to rotating power becomes lowest. On the one hand, at 90 deg. in crank angle after the top dead center, the friction loss is minimized, so that the efficiency of converting the up-and-down motion to rotational power becomes its highest. This practice can be understood readily from FIG. 2.
Similarly to the case where we make the bicycle advance efficiently, the system which optimizes the distribution of the amount of release with respect to the timing of releasing of the thermal energy is the "Energy transformation method and its system for piston reciprocating cycle" (Japanese Patent Application No. Hei 7-79292 and U.S. patent application Ser. No. 08/608,148) which this applicant had invented previously.
Shifting the timing at which the release of the thermal energy becomes the minimum from the time when the friction loss is maximized to the time when the friction loss is minimized, the system which the "Energy transformation method and its system for piston reciprocating cycle" which increases the efficiency of the case of converting the up-and-down motion to rotating power further is improved is the present invention.
Moreover, although this applicant had applied an energy conservation cycle engine that by reciprocating motion of a dual enlarged head piston, a pendulum arm is pendulated to rotate a crankshaft by the pendulating motion to produce rotational power, there has been disadvantages that due to the pendulating motion of the pendulum arm, the volume is increased and the structure is sophisticated, whereby an improvement of the energy conservation cycle engine such that a shortened stroke engine is used to rotate the crankshaft directly to convert to rotational power to produce a large output in spite of being compact and lightweight is provided.
The main object of the invention is to improve the various energy conservation cycle engine of the previous application, whereby NOx gases and the uncombusted portion can be eliminated, thereby environmental pollution being reduced.
In converting from a piston motion to rotational power also, there are the objects of providing an increase in a rotating force and utilizing the conserved thermal energy as rotational energy usefully.
Furthermore, it is an object that the friction loss and vibration of the cycle engine are reduced to reduce the equivalent to the maximum bearing load, thereby increasing the maximum combustion pressure and reducing CO.sub.2.
Moreover, as a further object, a thinning in wall thickness and reduction in weight of a main combustion chamber, weight reduction of a specific weight per output and an improvement of a scavenging effect are provided.
Furthermore, it is an object that, without reference to a kind of fuel, fuel ignition system, number of cycles, scavenging system and type of engine, while a specific output per weight is increased, the friction loss is reduced, thereby reducing environmental pollution including CO.sub.2.